Watthour meters are employed to measure the power consumed at a building or residential site. Recent developments have resulted in computerized, electronically programmable watthour meters. These watthour meters are designed to be programmed or reprogrammed at the place of installation, such as the customer residence or a customer building site. In addition, these meters have the capability for electronic readout of metered data, such as total kilowatt hours of consumption, demand kilowatt consumption, and the like.
Programming and reading of electronically programmable watthour meters is normally done by a utility company service person using a portable electronic reader/programing device. This device typically includes an optical adapter which attaches to a mating optical port having a coupler mounted through the meter dome to enable the reader/programmer to communicate with the electronics within the watthour meter.
Such optical parts utilize light receptive photo diodes and light emitting photo diodes which are mounted in a support through the cover or dome of a watthour meter the internal ends of the photo diode receivers and light transmitting photo diodes in the optical port are connected to the internal circuitry within the watthour meter. The adapter on the reader/programmer is attachable to the optical coupler support, typically through magnetic interaction to insure proper alignment of the adapter and coupler. In this manner, the reader/programmer held by the utility service person can communicate with the watthour meter circuitry.
Examples of typical optical couplers employed in watthour meters can be had by referring to U.S. Pat. Nos. 4,491,791; 4,491,792; 4,491,793; 5,742,512; 5,268,633; 5,057,767; and 5,027,056.
While the optical port provides an excellent communication path to allow programming and reading of programmable watthour meters, the optical port itself is subject to several problems. First, the positioning of the optical port on the exterior surface of the meter dome or cover places the optical port in a position for exposure to sunlight. The ultraviolet radiation causes the typically plastic covers over the photo diodes in the optical port to yellow or turn opaque over time thereby interfering with data communication through the optical port.
The exposed optical port also is susceptible to damage through vandalism as well as being easily accessible to unauthorized attempts to communicate with the watthour meter which may result in modification of stored data or stored thresholds, parameters and programs in the watthour meter.
It would be desirable to provide a device which addresses the above-described problems associated with the use of optical ports on electrical enclosures, such as watthour meters. It would also be desirable to provide such a device which is easy to use, does not interfere with data communication through the optical port when the electrical apparatus housed within the electrical enclosure is to be programmed or data is to be output to an external, portable reader/programmer. It would also be desirable to provide such a device which is capable of accepting a standard seal or padlock normally used with watthour meters to provide an indication of tampering with the device or its mounting on the optical port on the electrical enclosure.
The present invention is an electrical enclosure optical communication port seal which lockingly and sealably covers an optical communication port mounted in a support on an electrical enclosure, such as a watthour meter.
In one aspect, the seal includes a cap having a closed end portion adapted to be mountable over and encompass an optical port support on an electrical enclosure, and means for fixably securing the cap to the optical port support, with the closed end of the cap disclosed over the data communication end of the optical port support. A fastener is threadingly extendable through the cap into fixed engagement with the optical port support.
In another aspect, the seal includes at least one leg projecting from the cap. An aperture is formed in the at least one leg. Separation indicating means are mountable through the apertures in the leg and the fastener to indicate any separation of the cap from the support.
In another aspect, the cap includes a base fixedly disposed over the optical port support and having a through bore providing access to the optical port. A plate having a hooked-shape end is formed as part of the cap. Means are provided for pivotally attaching the hook on the plate to the base such that the plate is movable between a first position space from the base and exposing the optical port to access and a second position where the plate closes the bore in the base and blocks access to the optical port. A seal indicator is attachable to the base in the plate for indicating separation of the plate from the base.
In another aspect, the seal further includes an extension projecting from one portion of the cap. The extension defines a wall portion and a flange projecting from the wall portion. An aperture is formed in the flange aligned with an internally threaded bore formed in the cap. The threaded bore receives the securing means.
In this aspect, the cap further includes a sidewall extending from the closed end portion A shoulder is formed interiorly within the sidewall defining a resilient gasket mounting surface for forming a seal between the cap and a watthour meter. The shoulder optionally defines a thinner sidewall portion on the sidewall extending from the shoulder which is more easily deformable than the portion of the sidewall extending oppositely from the shoulder.
In another aspect, the securing means is in the form of a fastener threadingly extendable into the threaded bore in the cap. Finger grips surfaces may be formed on the fastener to facilitate hand rotation of the fastener. Optionally, an aperture is formed in the fastener for receiving a tool to facilitate rotation of the fastener. Optionally, an end portion of the fastener is formed with a plurality of angularly disposed exterior flats for receiving a tool to facilitate rotation of the fastener. Further, an end portion of the fastener may be formed with a plurality of interior flats opening through the end portion for receiving a tool interiorly within the end portion to facilitate rotation of the fastener. Yet further optionally, an end portion on the fastener is formed with a transversely extending slot, the slot opening through the end portion for receiving a tool to facilitate rotation of the fastener.
In yet another aspect, the securing means is in the form of a fastener having a tip end and a rotative force application end. A threaded portion extends from the tip end for threading engagement with the threads in the cap. A plurality of circumferentially spaced legs connect the threaded portion to the rotative force application end. The legs have a predetermined thickness such that the legs are deformable at a predetermined amount of rotative force applied to the rotative force application end.
In another aspect, the fastener preferably has a hardened tip.
In yet another aspect, an adhesive back strip is mountable over a data communication end of the optical port support. The strip is permanently deformable upon removable from the data communication end to indicate separation from the optical port support.
The optical communication port seal of the present invention address numerous problems associated with the use of optical ports on electrical enclosures, such as watthour meters. The optical communication port seal of the present invention is easy to use, does not interfere with data communication through the optical port when the electrical apparatus housed within the electrical enclosure is to be programmed or data is to be output to an external portable reader/programmer. At the same time, the inventive seal covers the optical port support protecting the optical port support from UV radiation, vandalism, etc. Further, the optical port seal of the present invention is adapted for receiving a standard seal or padlock normally used with watthour meters to provide an indication of tampering with the electrical device itself, or the cap on the optical port.